Question

How do different virtualization architectures compare and contrast with one another?

Answer 1

Q1) How do different virtualization architectures compare and contrast with one another?

Application Virtualization - Application virtualization allows users to run applications from devices that don’t possess the operating system the application requires. Another possible reason to use application virtualization is to run conflicting programs that can’t coexist on the same device. An example of this would be a user who needs to run two different versions of the same software. Two of the main application virtualization technologies are hosted applications and packaged applications.

Hosted solutions use servers to host applications and allow users to connect to the server from their device. The user sends keystrokes and mouse clicks to the server and the server sends screen changes to the user, while the server is actually running the applications. Many users can run applications on the server simultaneously so these servers must have a lot of resources. The user’s device doesn’t require a lot of resources since it’s not doing the work – one of the many benefits of application virtualization.

Packaged solutions package software within their own environment so they can run on devices with a different operating system than the application was built to run on like running an XP application on Windows 8. Packaged applications are often stored on network shares and then streamed to the user’s device.

2. Desktop Virtualization - Desktop Virtualization should be used if application virtualization can’t deliver the required applications and desktops. Application virtualization using the hosted model (XenApp or RDS) is preferred since you can get more users per server. Users that want specific operating systems other than Windows Server will need to have a virtual desktop. Some of the common benefits of desktop and application virtualization are user mobility, easy management of software installation, updates and patches.

3. Server Virtualization - Server virtualization separates the operating system from the computer hardware and allows the VM to be treated as a file. This provides for easy management and facilitates redundancy, high availability and disaster recovery.

Server virtualization gave birth to a new term referred to as elasticity. This gives us the ability to adjust our hardware resources to the current workload on the fly. When workload requirements are low, servers can be decommissioned. When workloads are high, servers are turned on. This along with server consolidation can save money on electricity and cooling.

Elasticity also allows companies to expand their data center resources on demand without buying any additional hardware. Services like Amazon Web Services and Microsoft Azure can provide resources as needed in a pay as you go model, allowing you to never have a shortage of resources and never paying for equipment that sits underutilized.

4. Storage Virtualization - Storage Virtualization goes hand in hand with server virtualization, as when both are used together they provide tremendous flexibility. It makes managing storage from multiple sources to be managed and utilized as a single repository. This simplifies utilization of Storage Area Networks (SAN’s). Because this storage isn’t married to any particular server, many servers can access the data stored on the SAN. Because servers (VM’s) are now in the form of a file, they can be stored on the SAN. If a host server goes down, another host can access that VM from the SAN and turn it on. This improves the high availability of these VM’s by facilitating mobility between which host server it will run on.

5. Network Virtualization - Network virtualization was developed by using the same concepts of server virtualization. Software Defined Networking uses virtual switches, routers, firewalls and load balancers. This allows IT staff to provision networks without disruption to the physical network while running traffic over the physical network. This allows VM’s to retain their security properties when moved from one host server to another that may be located on a different network. Server managers have the ability to configure virtual switches, routers, firewalls, load balancers, etc. without having to bother the network administrator.

All of these virtualization solutions offer many benefits. However, we often don’t have the budgets to accompany all of them, so how do we choose which to implement first? One thing to consider when deciding which virtualization solution to deploy is to adopt the solution that provides the maximum benefits. Another thing to consider is the ease of implementation. This may be easier said than done since they are mutually exclusive. However, often times solutions that are easy to implement can provide tremendous benefits immediately and that will give a quick ROI.

Please let me know in case of any clarifications required. Thanks!